We're having some trouble with a custom i.MX6Q board (based on sabreSD reference). It appears that our DDR3 is close to timing margins. I'd like to slow the DDR3 clock rate down to 396MHz. I tried plugging that value into the DDR3 programming spreadsheet and replacing the values in flash_header.S with the updated spreadsheet values. However, when u-boot comes up, its still showing 528MHz for the ddr clock. I also noticed that mx6q pll2 is set to 528MHz. Is there something else I need to do, like change pll2 somehow?